well, I wanted a village, and for that you need more than just two yukkuris XD
For what is worth you could've just been descriptive about the village, no need to make an actual character for that...
On the other side, Chen's story was too dispersive: it was either having chapters just for her (not a solution, since she's not a main character) or shifting the narration between THREE nests. Simply too much.
What I would've done is: introduce Chen and also Alice's two-timing, then keep narrating Marisa's story until she reaches Patche's nest. At that point, either have Chen be already there or let her appear later on (but not too late.)
After that, tell Chen's story by using short flashbacks (maybe disguised as dreams or memories) while continuing using the two-timing of Alice as a reason to cause tension inside the nest.
This tension would then lead to Marisa killing Chen once Patche's body is no more.
Granted, I would've also ended the story differently, but that's not important.
Next story (Anemone) is already turning to be at least a third of Frostchildren. Gut feeling tells me it'll be half the total lenght.
No thanks. There are already enough short tales (many of which, especially the most recent ones, are mine.)